Transcript BIODIVERSITY OF THE MEIOBENTHOS OF SANDY BEACHES IN

Academic Year 2000-2001
BIODIVERSITY OF THE MEIOBENTHOS
OF SANDY BEACHES IN ECUADOR WITH EMPHASIS
ON FREE-LIVING MARINE NEMATODES
By
ALBA KATHERINE CALLES PROCEL
Promotor
Prof. Dr. MAGDA VINCX
AIM
 To inventory the meiobenthos to higher
taxa (Guayas province in Ecuador).
 To identify the nematode communities to
genus level.
 To establish a relationship between the
nematode and the environmental factors.
 To establish the value of meiofauna
(nematodes)
as
bio-indicator
of
anthropogenic impact.
Biodiversity of Meiobenthos with emphasis on Free-Living Marine Nematodes/Ecuador
AREA OF STUDY
Position of Ecuador in South America
Olon
Cenaim
Pacific Ocean
San
SanPablo
Pablo
Salinas
Salinas
Guayas
Province
Artesanal beach
Playas
Playas
Tourist beach
N
Tourist/Artesanal beach
N
Biodiversity of Meiobenthos with emphasis on Free-Living Marine Nematodes/Ecuador
S
A
N
D
Y
SALINAS
SAN PABLO
B
E
A
C
H
E
S
 Salinas and Playas are
recreational beaches,
during weekends and
holidays.
 San Pablo and Cenaim
are lesser disturbed,
except for the ongoing
local artisanal fishery
activities
Biodiversity of Meiobenthos with emphasis on Free-Living Marine Nematodes/Ecuador
METHODOLOGY
Sampling: Four replicates; during
low tide level; cores of 3.2 diameter.
Fixation: 4% formalin.
Extraction: Decantation (ten times)
and centrifugation (three times)
with LUDOX (1.18 density).
Biodiversity of Meiobenthos with emphasis on Free-Living Marine Nematodes/Ecuador
METHODOLOGY
(Laboratory)
Counting meiofauna
and pick up nematodes
COUNTING
Glycerol-ethanol
(DE GRISSE, 1969b)
Paraffin is melted and
the slide is sealed
(COBB SLIDE, 1917)
MOUNTING
Biodiversity of Meiobenthos with emphasis on Free-Living Marine Nematodes/Ecuador
Salinity (PSU)
25
24.5
24
23.5
23
22.5
22
21.5
Playas
Salinas I
Cenaim
San Pablo
35
34
33
32
31
30
29
28
27
26
Playas
Olon I
Salinas I
Stations
4000
Chl a (ng/l)
Temperature (°C)
RESULTS
3000
2000
1000
0
Playas Salinas I Cenaim
Stations
San
Pablo
Olon I
Cenaim
Stations
San Pablo
Olon I
Biodiversity of Meiobenthos with emphasis on Free-Living Marine Nematodes/Ecuador
RESULTS
SPM (mg/l)
600
500
400
300
200
100
0
Playas
Salinas I Cenaim
San
Pablo
Olon I
POM (mg/l)
Stations
45
40
35
30
25
20
15
10
5
0
Playas
Salinas I
Cenaim
Stations
San Pablo
Olon I
Biodiversity of Meiobenthos with emphasis on Free-Living Marine Nematodes/Ecuador
RESULTS
Sediment analysis
Station
PLAYAS
SALINAS I
CENAIM
SAN PABLO
OLON I
Date
18.08.99
26.08.99
25.08.99
27.08.99
24.08.99
% sand (63µm)
99.40
98.40
99.30
98.60
98.10
% silt
0.60
1.60
0.70
1.40
1.90
Mean (µm)
319
197
205
233
160
Median (µm)
325
188
201
212
163
Mode (µm)
325
171
190
190
153
Skewness
-1.028
-1.777
-0.034
-1.135
-3.741
Kurtosis
5.051
14.110
0.986
10.080
29.300
Biodiversity of Meiobenthos with emphasis on Free-Living Marine Nematodes/Ecuador
RESULTS
Densities of meiofauna (ind./10 cm2)
2500
ind./10cm
2
2000
1500
1000
Nematoda
Gastrotricha
Turbellaria
Polycaheta
500
Pl
ay
as
Pl (A
ay )
Sa as
lin (B
as )
Sa I (
lin A)
as
Ce I (
na B)
i
Ce m (A
Sa naim )
nP (
B
Sa ablo )
n P (A
ab )
lo
O (B
lon )
O I (A
lon )
I(
B)
0
Copepoda
Biodiversity of Meiobenthos with emphasis on Free-Living Marine Nematodes/Ecuador
RESULTS
Composition of meiofauna taxa
9.3%
3.4%
0.1%
87.1%
Nematoda
Gastrotricha
Turbellaria
Otros
Biodiversity of Meiobenthos with emphasis on Free-Living Marine Nematodes/Ecuador
RESULTS
A total of 19 genera belonging to 14 families identified
Nematoda Genus diversity-indices (Hill’s numbers)
15
10
N0
N1
N2
Ninf
5
0
Olon I
(A)
Olon I
(B)
Playas
(A)
Playas Salinas I Salinas I Cenaim Cenaim San
(B)
(A)
(B)
(A)
(B)
Pablo
S tations
(A)
San
Pablo
(B)
Biodiversity of Meiobenthos with emphasis on Free-Living Marine Nematodes/Ecuador
RESULTS
k-dominance curve for the nematode genera
100
Playas (A)
Cumulative %
80
Playas (B)
Salinas I (A)
Salinas I (B)
60
Cenaim (A)
Cenaim (B)
40
San Pablo (A)
San Pablo (B)
20
Olon I (A)
Olon I (B)
0
1
2
3
4
5
6
7
8
9
Genus rank
10 11 12 13 14
Biodiversity of Meiobenthos with emphasis on Free-Living Marine Nematodes/Ecuador
RESULTS
Relative abundance of nematode feeding type
(according to Wieser) per station
100
80
60
40
Stationes
Olon I (B)
Olon I (A)
San Pablo (B)
San Pablo (A)
Cenaim (B)
Cenaim (A)
Salinas I (B)
Salinas I (A)
0
Playas (B)
20
Playas (A)
%
2B
2A
1B
1A
Biodiversity of Meiobenthos with emphasis on Free-Living Marine Nematodes/Ecuador
RESULTS
Relative abundance of nematode structure per station
100%
80%
juveniles
60%
females
40%
males
Olon I (B)
Olon I (A)
San Pablo (B)
Stations
San Pablo (A)
Cenaim (B)
Cenaim (A)
Salinas I (B)
Salinas I ( A)
Playas (B)
0%
Playas (A)
20%
Biodiversity of Meiobenthos with emphasis on Free-Living Marine Nematodes/Ecuador
RESULTS
TWINSPAN dendrogram based on the abundance (%) of
nematode genera (Cut level: 0, 2, 5, 10 and 20)
GENERA
Gonionchus
Odontanticoma
Sabatiera
Halalaimus
Olon I (A)
Olon I (B)
Playas (A)
Playas (B)
Salinas (A)
Salinas (B)
Cenaim (A)
Cenaim (B)
San Pablo (A)
San Pablo (B)
Biodiversity of Meiobenthos with emphasis on Free-Living Marine Nematodes/Ecuador
RESULTS
Axis 2
Play-B
% sand
Skewne
Mean
Median
Salin-B
SPM
Chla
Tem
p
POM
SanP-B
Cena-B
Cena-A
SanP-A
Play-A
Salin-A
Salinity
% silt
Olon-A
Olon-B
Axis 1
Biodiversity of Meiobenthos with emphasis on Free-Living Marine Nematodes/Ecuador
RESULTS
Metadesmolaimus plot per station
Paracyatholaimus plot per station
Play-B
Play-B
Axis 2
Salin-B
Play-A
SanP-A
SanP-B
Axis 2
Cena-B
Salin-B
Cena-A
Play-A
Salin-A
SanP-B
SanP-A
Cena-B
Cena-A
Salin-A
Olon-A
Olon-A
Olon-B
Olon-B
Axis 1
Axis 1
Metadesmolaimus
Paracyatholaimus
Axis 1
r = -.795 tau = -.733
Axis 2
r = .113 tau = -.244
Axis 1
r = .005 tau = .067
Axis 2
r = -.660 tau = -.244
Biodiversity of Meiobenthos with emphasis on Free-Living Marine Nematodes/Ecuador
Gonionchus sp. n.
Six lips very high and weakly
cuticularized
Amphid circular
Longitudinal ornamentation
(as rod-like structures)
Biodiversity of Meiobenthos with emphasis on Free-Living Marine Nematodes/Ecuador
Gonionchus sp. n.
Longitudinal ornamentation
starts at irregular levels in the
cervical region and go
throughout the whole body
length.
Protrusion of the spicules
Biodiversity of Meiobenthos with emphasis on Free-Living Marine Nematodes/Ecuador
CONCLUSION
• Meiofauna: highest density
lowest density
• Chlorophyll a, SPM and POM
meiofauna density
Cenaim (2226-2544 ind./10 cm2)
Salinas (349-558 ind./10 cm2)
(Salinas and Olon)
• NEMATODES: 312-2398 ind./10cm2
87% of meiofauna
• Gastrotricha: second most dominant taxon of meiofauna; mainly in
Playas (324-389 ind./10 cm2)
• Diversity: higher in Playas B, (N0= 14); lowest in San Pablo, (N0=6)
nematode density (Playas= 614, S. Pablo= 2190 ind./10cm2).
HIGHESTdiversity
LOWEST density
• Description of one new species of Gonionchus
THE END